i have an automatic and it doesnt have a tack on the gauges if i gor like reverse gauges how woul i put a tack is there a plug or something?

 

a very simple solution to what you are asking is this.

you can buy a universal guage pod from most kragens, auto zone or even some chain stores like walmar kmart etc..
and you could buy a small tach that will fit it, and mount it on the frame just past the front door. it looks clean and is visable at a glance. if you dont understand what im talking about, you can do a search from yahoo and look for guage pods.